Climate change is a change in the long-term global temperature normal, or average, due to an increase in greenhouse gasses in the atmosphere and land use changes that are causing the average global temperature to rise. Since the end of the last glaciation period, the Earth’s climate has remained in a relatively stable and balanced state but it is shifting out of that balance. Over 97% of climate scientists agree that climate change is occurring due to human activities.

This graph shows global temperature data as recorded by four international institutions. These records show a consensus on global temperature increases since 1880 and all four show that the last decade has been the warmest on record. In 2016, the average global temperature was at a record high at 1.1°C warmer than the pre-industrial period and 0.83°C above the average from 1961-1990 as recorded by the World Meteorological Organization.

What does the Mean for Saint John?

Local and regional climates will respond differently to global warming based on the unique set of geographic conditions in each area. For example, Saint John has cooler summers and warmer winters than Fredericton because of its location on the coast; therefore, climate change will affect each of these cities in different ways. The Climate Change Secretariat of the Government of New Brunswick has released New Brunswick’s Future Climate Projections: AR5 Data and Maps to help communities understand local changes and prepare for impacts over the course of this century. These local projections were developed from the Intergovernmental Panel on Climate Change’s projections in the Fifth Assessment Report (AR5).

Impacts in Saint John

Climate change is expected to have a range of impacts in Saint John. The temperatures in New Brunswick are expected to rise faster than global temperatures. The average temperature has already increased by 1.1°C in the last 30 years and is expected to rise by 2-3°C by 2050 as compared to the period from 1961-1990. The impacts for Saint John due to these increases are as follows:

Increased annual and seasonal temperatures leading to more variable weather patterns

A combination of high tide and storm surge in Saint John on October 29, 2015 gave an indication of where coastal infrastructure is already at risk to flooding and erosion. This image shows waves crashing over the rocks and into the beach volleyball courts next to Loyalist Plaza. Coastal infrastructure will be at greater risk in the future due to sea level rise which will contribute to higher tide levels over the rest of this century and more frequent storm surges and extreme weather events.